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Fill in blanks activity for writing ones space address

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Fill in blanks activity for writing ones space address

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The expanding balloon analogy for cosmological models is shown below at two different times. A common misconception is that the balloon is expanding into empty space that is "beyond the Universe" and that it is expanding from a single point in the center of the balloon. But the balloon analogy is a 2-dimensional model, and the center of the balloon and the space around are not part of the 2-dimensional Universe. In our 3-dimensional Universe, these points could only be reached by traveling in a 4th spatial dimension (not the time dimension of 4-D spacetime), but there is no evidence that this dimension exists.

Note that the galaxies (yellow blobs) do not grow, but the distance between galaxies grows, and that the photons move and shift from blue to red as the Universe expands.
This animation shows an expanding universe model with yellow blobs for galaxies and moving, redshifting photons. The animation starts at a redshift of 3 when the Universe was 4 times smaller than it is now, and finishes at the present. Taken literally, the ratio of the radius of the "balloon" to the Hubble distance c/H o implies an Omega = 2 currently and Omega = 1.14 at z = 3. Note that the galaxies do not expand: bound systems are not affected by the expansion of the Universe. Also note that the speed of light relative to the nearby galaxies is a constant - if your browser is properly using the duration values in the animated GIF file.

Ned Wright's Home Page

FAQ | Tutorial : Part 1 | Part 2 | Part 3 | Part 4 | Age | Distances | Bibliography | Relativity

© 1998 Edward L. Wright. Last modified 8-May-1998

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The expanding balloon analogy for cosmological models is shown below at two different times. A common misconception is that the balloon is expanding into empty space that is "beyond the Universe" and that it is expanding from a single point in the center of the balloon.

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Understanding Earths  place in the universe

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Understanding Earths  place in the universe

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Playing quizzes is free! We send trivia questions and personality tests every week to your inbox. By clicking "Sign Up" you are agreeing to our privacy policy and confirming that you are 13 years old or over.

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Playing quizzes is free! We send trivia questions and personality tests every week to your inbox. By clicking "Sign Up" you are agreeing to our privacy policy and confirming that you are 13 years old or over.

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explains the Hubble telescope, its relevance to science and how it works

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Hubble's launch and deployment in April 1990 marked the most significant advance in astronomy since Galileo's telescope 400 years ago. Thanks to five servicing missions and more than 25 years of operation, our view of the universe and our place within it has never been the same.

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the big bang theory explained in detail

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For centuries, humans have gazed at the stars and wondered how the universe developed into what it is today. It's been the subject of religious, philosophical, and scientific discussion and debate. People who have tried to uncover the mysteries of the universe's development include such famous scientists as Albert Einstein, Edwin Hubble and Stephen Hawking. One of the most famous and widely accepted models for the universe's development is the big bang theory.

Although the big bang theory is famous, it's also widely misunderstood. A common misperception about the theory is that it describes the origin of the universe. That's not quite right. The big bang is an attempt to explain how the universe developed from a very tiny, dense state into what it is today. It doesn't attempt to explain what initiated the creation of the universe, or what came before the big bang or even what lies outside the universe.

Another misconception is that the big bang was a kind of explosion. That's not accurate either. The big bang describes the expansion of the universe. While some versions of the theory refer to an incredibly rapid expansion (possibly faster than the speed of light), it's still not an explosion in the classic sense.

Summing up the big bang theory is a challenge. It involves concepts that contradict the way we perceive the world. The earliest stages of the big bang focus on a moment in which all the separate forces of the universe were part of a unified force. The laws of science begin to break down the further back you look. Eventually, you can't make any scientific theories about what is happening, because science itself doesn't apply.

So what's the big bang theory in a nutshell?

The Big Bang Theory FAQ

Who discovered the big bang theory?

How did the big bang happen from nothing?

What is the big bang theory in simple terms?

What does the big bang theory tell us?

How did the big bang start?

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For centuries, humans have gazed at the stars and wondered how the universe developed into what it is today. It's been the subject of religious, philosophical, and scientific discussion and debate. People who have tried to uncover the mysteries of the universe's development include such famous scientists as Albert Einstein, Edwin Hubble and Stephen Hawking.

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summarizes some of the different theories that students could chose to make a model on

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"In the beginning" -- before the 1920s, these words had no place in our scientific understanding of the universe. Astronomers believed the cosmos to be eternal and unchanging. We knew of only one galaxy and a few million visible stars, and this was the scope of our observable universe.

Then astronomer Edwin Hubble observed, courtesy of redshift, distant galaxies speeding away from each other and formulated Hubble's Law to explain the universe's uniform expansion. Redshift just refers to a distant celestial body's shift toward longer, or redder, wavelengths, compliments of the Doppler effect.

Meanwhile, physicist Albert Einstein had just completed his general theory of relativity, which provided a model of a finite, homogenous cosmos shaped by gravity. These efforts laid most of the groundwork for a flurry of new discoveries and fresh theories in the decades ahead.

Our modern scientific understanding of the universe provides a kind of road map through time. Based in Hubble and Einstein and corroborated by such discoveries as the abundance of light elements and the cosmic microwave background radiation, this map points back 13.7 billion years to an event we know as the big bang.

At this point in the ancient past, there was no such thing as time or space. There was just a single hot, condensed point -- a singularity -- containing all matter in the universe. In addition, all four fundamental forces (the gravitational, electromagnetic, strong and weak forces) were unified as a single force. This unified period, called the Planck epoch, lasted 10⁻⁴³ seconds. Then the universe expanded at a rate faster than the speed of light, growing from subatomic to golf-ball size almost instantaneously. Scientists call this the inflationary period.

The universe then expanded outward in a flood of superheated subatomic particles. Three seconds after the big bang, space cooled enough for these particles to form elements. Some 300 million years later, stars and galaxies formed as well. (For more detailed information on these beginning steps, read How the Big Bang Theory Works.

The big bang theory still provides the best model for how the universe arose, but it's not the only theory we have. For example, the steady-state theory modeled a universe with a consistent density that appears to expand due to the constant generation of new matter. Support for it, however, largely died out, thanks to the discovery of the cosmic microwave background ( CMB) in 1965. The CMB was, in essence, the radiation signature of the early, expanding universe.

The Ekpyrotic model suggests the universe formed due to the collision of two separate universes in the fourth dimension. And the big bounce theory suggests our universe is caught in an eternal cycle of big bangs and big crunches.

You can think of such theories and models as piers extending into the cosmic unknown. Some provide us with solid enough footing to observe and test the universe as we steadily determine exactly where and what we are in it.

Explore the links below for even more cosmological quandaries.

Related HowStuffWorks Articles

More Great Links

Sources

"Edwin Powell Hubble." EdwinHubble.com. May 3, 2002. (April 30, 2010)http://www.edwinhubble.com/hubble_bio_001.htm

"History of the Universe Timeline." PBS Mysteries of Deep Space. (April 30, 2010)http://www.pbs.org/deepspace/timeline/

Nave, Rod. "Models of Earlier Events." GSU Hyper Physics. (April 30, 2010)http://hyperphysics.phy-astr.gsu.edu/Hbase/Astro/planck.html#c7

"Scientific Evidence for a Beginning." Harvard House. (April 30, 2010)http://www.harvardhouse.com/Scientific_Evidence_for_Beginning.htm

"The Big Bang." NASA. April 5, 2010. (April 30, 2010)http://science.nasa.gov/astrophysics/focus-areas/what-powered-the-big-bang/

Turner, Michael S. "The Origin of the Universe." Scientific American. September 2009. (April 30, 2010)http://www.scientificamerican.com/article.cfm?id=origin-of-the-universe

"Universe 101: Big Bang Theory." NASA. April 16, 2010. (April 30, 2010)http://map.gsfc.nasa.gov/universe/

Wanjek, Christopher ."Ringside Seat to the Universe's First Split Second." NASA. March 16, 2006. (April 30, 2010)http://www.nasa.gov/vision/universe/starsgalaxies/wmap_pol.html

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"In the beginning" -- before the 1920s, these words had no place in our scientific understanding of the universe. Astronomers believed the cosmos to be eternal and unchanging. We knew of only one galaxy and a few million visible stars, and this was the scope of our observable universe.

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                      Sample Articles for research on origins of the universe:

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                      Sample Articles for research on origins of the universe:

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This illustration summarizes the almost 14-billion-year-long history of our universe. It shows the main events that occurred between the initial phase of the cosmos - where its properties were almost uniform and punctuated only by tiny fluctuations - to the rich variety of cosmic structure that we observe today, ranging from stars and planets to galaxies and galaxy clusters.

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reading comprehension incl. numeracy questions

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reading comprehension incl. numeracy questions

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            Activities for literacy and numeracy

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            Activities for literacy and numeracy

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     peer reviewed papers on science pedagogy

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     peer reviewed papers on science pedagogy

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make the model from recycled materials like a cereal box

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make the model from recycled materials like a cereal box

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Worksheet of questions on The Big Bang video

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Worksheet of questions on The Big Bang video

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What Is The Big Bang Theory? | The Dr. Binocs Show - Best Learning Videos For Kids | Peekaboo Kidz

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                 Some resources for the lesson

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                 Some resources for the lesson

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Science Collaborative Planning Document - padlet

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Reflection to changes in specification for Junior Cycle

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Reflection to changes in specification for Junior Cycle

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by making 3 cubes that fit into eachother, it allows students to visualize where the Earth is in the universe.
Earth is in the solar system which is in the universe

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'A representation of an idea, an object or even a process or a system that is used to describe and explain phenomena that cannot be experienced directly'

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In science, a model is a representation of an idea, an object or even a process or a system that is used to describe and explain phenomena that cannot be experienced directly. Models are central to what scientists do, both in their research as well as when communicating their explanations.

Models are a mentally visual way of linking theory with experiment, and they guide research by being simplified representations of an imagined reality that enable predictions to be developed and tested by experiment.

Why scientists use models

Models have a variety of uses - from providing a way of explaining complex data to presenting as a hypothesis. There may be more than one model proposed by scientists to explain or predict what might happen in particular circumstances. Often scientists will argue about the 'rightness' of their model, and in the process, the model will evolve or be rejected. Consequently, models are central to the process of knowledge-building in science and demonstrate how science knowledge is tentative.

Think about a model showing the Earth - a globe. Until 2005, globes were always an artist's representation of what we thought the planet looked like. (In 2005, the first globe using satellite pictures from NASA was produced.) The first known globe to be made (in 150BC) was not very accurate. The globe was constructed in Greece so perhaps only showed a small amount of land in Europe, and it wouldn't have had Australia, China or New Zealand on it! As the amount of knowledge has built up over hundreds of years, the model has improved until, by the time a globe made from real images was produced, there was no noticeable difference between the representation and the real thing.

Building a model

Scientists start with a small amount of data and build up a better and better representation of the phenomena they are explaining or using for prediction as time goes on. These days, many models are likely to be mathematical and are run on computers, rather than being a visual representation, but the principle is the same.

Using models for predicting

In some situations, models are developed by scientists to try and predict things. The best examples are climate models and climate change. Humans don't know the full effect they are having on the planet, but we do know a lot about carbon cycles, water cycles and weather. Using this information and an understanding of how these cycles interact, scientists are trying to figure out what might happen. Models further rely on the work of scientists to collect quality data to feed into the models. To learn more about work to collate data for models, look at the Argo Project and the work being done to collect large-scale temperature and salinity data to understand what role the ocean plays in climate and climate change.

For example, they can use data to predict what the climate might be like in 20 years if we keep producing carbon dioxide at current rates - what might happen if we produce more carbon dioxide and what would happen if we produce less. The results are used to inform politicians about what could happen to the climate and what can be changed.

Another common use of models is in management of fisheries. Fishing and selling fish to export markets is an important industry for many countries including New Zealand (worth $1.4 billion dollars in 2009). However, overfishing is a real risk and can cause fishing grounds to collapse. Scientists use information about fish life cycles, breeding patterns, weather, coastal currents and habitats to predict how many fish can be taken from a particular area before the population is reduced below the point where it can't recover.

Models can also be used when field experiments are too expensive or dangerous, such as models used to predict how fire spreads in road tunnels and how a fire might develop in a building.

How do we know if a model works?

Models are often used to make very important decisions, for example, reducing the amount of fish that can be taken from an area might send a company out of business or prevent a fisher from having a career that has been in their family for generations.

The costs associated with combating climate change are almost unimaginable, so it's important that the models are right, but often it is a case of using the best information available to date. Models need to be continually tested to see if the data used provides useful information. A question scientists can ask of a model is: Does it fit the data that we know?

For climate change, this is a bit difficult. It might fit what we know now, but do we know enough? One way to test a climate change model is to run it backwards. Can it accurately predict what has already happened? Scientists can measure what has happened in the past, so if the model fits the data, it is thought to be a little more trustworthy. If it doesn't fit, it's time to do some more work.

This process of comparing model predictions with observable data is known as 'ground-truthing'. For fisheries management, ground-truthing involves going out and taking samples of fish at different areas. If there are not as many fish in the region as the model predicts, it is time to do some more work.

Learn more about ground truthing in Satellites measure sea ice thickness. Here scientists are validating sateliite data on ice thickness in Antarctica so the data can be used to model how the Earth's climate, sea temperature and sea levels may be changing.

Nature of science

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In science, a model is a representation of an idea, an object or even a process or a system that is used to describe and explain phenomena that cannot be experienced directly. Models are central to what scientists do, both in their research as well as when communicating their explanations.

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Earth and Space 2:
Explore a scientific model to illustrate the origins of the Earth